Durak means "fool", and that is the only thing at stake: there is no winner's score, just a loser. Players take turns attacking each other with cards, and the defender either beats every card thrown at them or picks the whole lot up. A game takes about 15 minutes.

What You Need

Players: 2-6. Four is ideal.
Deck: 36 cards - 6, 7, 8, 9, 10, J, Q, K, A of each suit. Strip a standard deck of everything from 2 to 5.
Extras: Nothing.

Key Terms

Attacker: The player throwing cards at the defender.
Defender: The player to the attacker's left, who must beat each card.
Beat: Covering an attacking card with a higher card of the same suit, or with any trump.
Trump: The suit that beats every non-trump card, decided by the card placed under the stock.
Durak: The fool - the last player left holding cards.

Setup

Deal 6 cards to each player.
Place the rest face down as the stock, then turn the bottom card of the stock face up and slide it partly under the pile. Its suit is trump for the whole game and it is the last card that will be drawn.
Whoever holds the lowest trump card attacks first.

How to Play

The attacker plays a card face up in front of the defender.
The defender must beat it with a higher card of the same suit, or with any trump. A trump attack can only be beaten by a higher trump.
If the defender beats it, other players may add more attacking cards - but only of ranks already on the table. The defender must beat each new one.
An attack cannot use more cards than the defender holds, and is capped at six cards in total.
If the defender beats everything, all the cards are discarded out of the game and the defender becomes the next attacker.
If the defender gives up, they take every card on the table into their hand, and the turn passes over them to the next player.
After each round, everyone draws back up to six cards from the stock, attacker first. Once the stock is empty, no more drawing happens.

Scoring & Winning

There is no scoring. Players who run out of cards after the stock is exhausted simply leave the game safely.
The last player still holding cards is the durak. Everyone else has effectively won.
Traditionally the durak deals the next game.

Example

The attacker plays the 9♣ and you defend with the J♣. Another player then throws in a 9♦ because 9s are already on the table, and you must beat that one too or pick up everything.

Variations

Podkidnoy Durak: the version described above, where anyone may throw in matching ranks. This is the standard.
Perevodnoy (transfer) Durak: you may pass the attack along to the next player by adding a card of the same rank instead of defending.
Team play: with four or six players, partners sit alternately and the losing pair are the fools.

Tips for New Players

Trumps are precious. Beating a low card with a trump early usually costs you more than picking up.
Watch how many cards the defender holds - you cannot attack with more cards than they have.
Once the stock runs out the game changes completely. Save trumps for that phase, when nobody is drawing replacements.